#container {
  margin: 0 auto;
  padding: 0;
  width: 1200px;
  border: 10px solid #ffffe1;
}

/* 头部区域 */
#header {
  background-color: #ffffe1;
  text-align: center;
  padding: 20px;
}

/* 导航条 */
#nav {
  width: 25%;
  height: 500px;
  float: left;
  background-color: white;
}

#nav ul {
  margin: 0px;
  padding: 0px;
  border: 0px;
}

#nav ul li {
  list-style: none;
}

/* 导航链接 */
#nav ul li a {
  /* float: center; */
  display: block;
  color: blue;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}
 
/* 链接 - 修改颜色 */
#nav ul li a:hover {
  background-color: #ddd;
  color: black;
}

#nav ul li ul {
  display: none;
}

#nav li:hover ul {
  display: block;
}
 
#main {
  width: 75%;
  height: 500px;
  float: left;
  text-align: center;
  background-color: #0FF;
}

/*底部区域*/
#footer {
  background-color: #F1F1F1;
  text-align: center;
  padding: 10px;
}
